Boston Molasses Tank Explosion Killed 21, Hurt 150 Others

Wednesday, January 15, 1919, was much like most other Wednesdays in Boston when suddenly, at about 12:30 p.m., KABOOM!

A large storage tank in the North End waterfront neighborhood exploded. The tank, filled with 2.3 million gallons of molasses weighing about 13,000 short tons (12,000 metric tons), blew up.

The explosion sent a wave of sticky molasses rushing through the streets at an estimated 35 miles per hour, resulting in 21 deaths and some 150 injuries. For decades, residents said they could still smell molasses on hot days in Boston.

The event became known as the Great Molasses Flood and the Boston Molasses Disaster.

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The explosion occurred at the Purity Distilling Company at 529 Commercial Street near Keany Square. The large tank stored molasses offloaded from ships that would later be transferred by pipeline to another facility in Cambridge.

The molasses tank was about 50 feet tall and 90 feet in diameter. "Cylinder stress failure" was the official cause of the explosion.

According to witnesses, the ground shook, and they heard a roar as the tank collapsed. The sound of the rushing molasses was like a long rumble, similar to a passing train.

The Boston Post and Boston Globe both reported massive structural damage, with buildings swept from their foundations and a truck tossed into Boston Harbor. The Globe reported that people "were picked up by a rush of air and hurled many feet."

Crews used salt water and sand to clean up the sticky mess. Reports say the harbor remained brown until summer.

Those killed included laborers, homemakers, a firefighter and several children. The dead ranged in age from 10 to 78 years old.